Pilot burner means or the like

ABSTRACT

1,115,999. Controlling gas burners. ROBERTSHAW CONTROLS CO. 1 Dec., 1965 [2 Dec., 1964], No. 51061/65. Headings F4F and F4T. An oven burner 51, Fig. 8 is ignited by a pilot burner 10, the flame of which is enlarged at ignition to provide both an igniting flame and a heating flame, the latter heating a temperature sensing bulb 47 adapted to open a safety valve 58 supplying the oven burner. A flame shield 13, Fig. 2, associated with the pilot burner comprises a first portion 28 having an opening 29 through which the igniting flame issues and a second slotted portion 32 which directs part of the enlarged flame downwardly towards a pair of spaced ears 40, 41 formed on the end of the second portion and adapted to support the sensing bulb 47. The pilot burner comprises a bent conduit 15 brazed to a hexagonal retainer 17 having a threaded inlet for connection to a fuel line and having a transverse opening 19 through which air is drawn. In a modification. Figs. 10-14 (not shown), the pilot burner directs the Mixture upwardly on to an inclined apertured first part of the shield and the second slotted part is disposed horizontally. The safety valve 58, Fig. 7 (not shown), comprises an expansible element (65) connected by a conduit (49) to the temperature sensing element 47 and to a valve member (63) through a snap action lever and spring device (64). The fuel supply to the oven and pilot burners is controlled by a device 52, Fig. 8, comprising a valve 57 opened by a knob 56 to connect a fuel manifold 54 to a chamber 55 and to a chamber 77. The pilot burner is supplied continuously by to passage 74 to provide small standby flame and the enlarged pilot flame is produced by an additional of fuel to the pilot burner by the opening of a ball valve 79 between the chamber 77, and a third chamber 76. The ball valve 79 is opened by a lever 81 fulcrumed on the end 83 of an axially movable pin 84 connected to the knob 56. The end of the lever remote from the ball valve is connected to an expansible element 87 connected to a second temperature sensing element 88 in the oven. When the oven temperature is below the temperature set by the knob 56, the ball valve opens and the enlarged pilot flame actuates the safety valve 58 and fuel flows from the chamber 55 to the oven burner.

March 14, 1967 RIEHL PILOT BURNER MEANS OR THE LIKE 4 Sheets-Sheet 1Filed Dec. 2, 1964 IIIII L was;

INVENTOR. FRED RIEHL HIS ATTORNEYS March 14, 1967 F. RIEHL 3,308,871

PILOT BURNER MEANS OR THE LIKE Filed Dec. 2, 1964 4 Sheets-Sheet 2 86 PHH INVENTOR. FRED RIEHL HIS ATTORNEYS March 14, 1967 RlEHL PILOT BURNERMEANS OR THE LIKE 4 Sheets-Sheet 3 Filed Dec. 2, 1964 INVENTOR. FREDRIEHL OOOOOOOOOOOOOOOO HIS ATTORNEYS March 14, 1967 F. RIEHL 3,308,871

PILOT BURNER MEANS OR THE LIKE Filed D60. 2, 1964 4 Sheets-Sheet 4INVENTOR. FRED RIEHL HIS ATTORNEYS United States Patent 3,308,871 PILOTBURNER MEANS OR THE LIKE Fred Riehl, Greensburg, Pa., assignor toRobertshaw Controls Company, Richmond, Va., a corporation of DelawareFiled Dec. 2, 1964, Ser. No. 415,410 21 Claims. (Cl. 158143) Thisinvention relates to an improved pilot burner system or the like as wellas to improved parts for such a pilot burner system or the like.

It is well known that small pilot burners are provided for fuel burningapparatus or the like wherein the pilot burner means is mounted adjacentto the main burner means of the apparatus or the like so that the flameissuing from the pilot burner means will ignite the fuel issuing fromthe main burner means as the main burner means is cycled between its offand on positions.

According to the teachings of this invention, an improved pilot burnermeans is provided wherein the structure provides improved mixing betweenthe fuel and the air supply for eflicient burning thereof at the outletend of the burner means, the burner means additionally having a flameshield so constructed and arranged that the same will cause the flame toappropriately heat a temperature sensing bulb when the flame at thepilot burner means is projected outwardly therefrom in a mannerhereinafter described.

However, the improved pilot burner means of this invention is adapted tohave a standby flame thereof projected into main burner ignitingposition before the heater flame thereof is large enough to heat thetemperature sensing bulb.

Further, the pilot burner means of this invention is so constructed andarranged that the same can be formed of a relatively few parts in arelatively inexpensive manner to provide an economical pilot burnermeans or the like.

Accordingly, it is an object of this invention to provide an improvedpilot burner system having one or more of the novel features set forthabove or hereinafter shown or described.

Another object of this invention is to provide improved parts for such apilot burner system or the like.

Other objects, uses and advantages of this invention are apparent from areading of this description which proceeds with reference to theaccompanying drawings forming a part thereof and wherein:

FIGURE 1 is a side view of the improved pilot burner means of thisinvention.

FIGURE 2 is a top view of the pilot burner means illustrated in FIGURE1.

FIGURE 3 is a cross-sectional view taken on line 33 of FIGURE 1.

FIGURE 4 is a view similar to FIGURE 1 with the flame shield thereofshown in cross section.

FIGURE 5 is a view similar to FIGURE 4 and illustrates the pilot burnermeans in another operating position thereof.

FIGURE 6 is a view similar to FIGURE 4 and illustrates the pilot burnermeans in another operating position thereof.

FIGURE 7 is schematic view illustrating the improved system of thisinvention.

FIGURE 8 is also -a schematic view illustrating various parts of thesystem of this invention in cross section.

FIGURE 9 is a view similar to FIGURE 1 illustrating another pilot burnermeans of this invention.

FIG. 10 is a top view of the structure of FIGURE 9.

FIGURE 11 is a cross-sectional view taken on line 1111 of FIGURE 9.

FIGURES 12-14 are views similar to FIGURES 4-6 Patented Mar. 14, 1967and illustrate the pilot burner means of FIGURE 9 in various operatingpositions thereof.

While the various features of this invention are hereinafter describedand illustrated as being particularly adapted for providing a pilotburner means for a fuel burning main burner system means, it is to beunderstood that th evarious features of this invention can be utilizedsingly or in any combination thereof to provide burner means for othersystems or the like.

Therefore, this invention is not to be limited to only the embodimentsillustrated in the drawings, because the drawings are merely utilized toillustrate one of the wide variety of uses of this invention.

Referring now to FIGURE 1, the improved pilot burner means of thisinvention is generally indicated by the reference numeral 10 andcomprises a conduit means 11, bracket means 12, flame shield 13 andtemperature sensing bulb 47 interconnected together in a mannerhereinafter described.

The conduit means 11 includes a tubular conduit 15 having one end 16received in a hollow hexagonal retainer 17 and secured thereto bybrazing or the like, the hexagonal retainer 17 having a threaded portion18 to interconnect the interior thereof with a fuel supply line (notshown). The retainer 17 has a transverse opening 19 passing completelytherethrough and being in communication with the axial bore thereinwhich is aligned with the bore in the conduit 15 so that when fuel flowsfrom the inlet end 18 of the conduit means 11 to the outlet end 20thereof (FIGURE 4) the flow of fuel causes air to be drawn into theretainer '17 through the opening 19 to be mixed with the fuel forsubsequent ignition thereof.

The conduit 15 is bent or angled at 21 between the ends 18 and 20thereof to provide a tortuous path for the fuel and air passingtherethrongh so that a turbulence is created at the elbow 21 tothoroughly mix the fuel and air flowing through the conduit 15.

The hexagonal retainer v17 is received in a hexagonal opening 22 formedthrough a tang 23 of the mounting bracket 12 in the manner illustratedin FIGURES 1 and 2, the hexagonal retainer 17 being subsequently brazedin the opening 22 to securely fasten the conduit means 11 to the bracket12.

The bracket 12 can be provided with a plurality of openings or slots 25,26 and 27 for mounting the pilot burner means 10 to any desiredstructure, such as a main burner means or the like so that the pilotburner means can ignite fuel issuing from the main burner means in amanner hereinafter described.

The flame shield 13 is formed with a first portion 28 thereof extendingover and beyond the outlet end 20 of the conduit means 11, the firstportion 28 of the flame shield 13 having a suitable opening 29 formedtherein and through which a small standby flame 30 of the pilot burnermeans 10 can issue in the manner illustrated in FIGURE 4 when a minimumamount of fuel is flowing to the pilot burner means 10 in a mannerhereinafter described.

When forming the opening 29 in the flame shield 13, a smallsubstantially triangular tang 31 is carved therefrom and bent over instacked relation against the outlet end 20 of the conduit means 11 inthe manner illustrated in FIGURES 3 and 4, the tang 31 partially closingthe end 20 of the conduit means 11 and extending from the upper portionthereof to a point substantially spaced from the lower portion of theoutlet end 20 for a purpose now to be described.

Since the tang 31 provides an obstruction to the fuel issuing from theoutlet end 20 of the conduit means 11, it can be seen that the fuelimpinging thereagainst will have to flow around the tang 31 and, thus,will,

cause turbulence of the fuel issuing from the outlet end 20 of theconduit 11 to further mix the fuel and air flowing through the conduit15 for proper ignition thereof.

The flame shield 13 also includes a second portion 32 integrallyinterconnected to the first portion 28 and being disposed angularlyrelative thereto whereby the second portion 32 is directed across theoutlet end in the manner illustrated in FIGURE 5, the portion 32 havinga slit or slot 33 formed therein and terminating short of the free end34 of the second portion 32 of the flame shield 13.

In this manner, when an additional supply of fuel is fed to the pilotburner means 10 in a manner hereinafter described, the increased forceof the flow of'fuel through the conduit means 11 will cause the standbyflame 30 to increase in size in the manner illustrated in FIGURE 5,while part of the flame impinges against the angularly disposed portion32 of the flame shield 13 whereby a flame 35 can issue through the slit33 and not be extinguished by the portion 32 even though the portion 32is directing the flame 35 downwardly to produce a heater flame 36 in themanner illustrated in FIGURE 6 beyond the free end 34 of the portion 32of the flame shield 13 for a purpose hereinafter described.

The flame shield 13 has a pair of opposed depending flanges 37 extendingdownwardly from the side edges of the portions 28 and 32 thereof in themanner illus trated in the drawings whereby the flame shield 13 has |asubstantially inverted U-shaped cross-sectional configiuration asillustrated in FIGURE 3 throughout substantially the entire length ofthe flame shield 13. The flame shield 13 also has a front dependingflange 38 provided with an opening 39 therein and through which theoutlet end 20 of the conduit means 11 can project, the outlet end 20 ofthe conduit means 11 being suitably brazed in the openings 39 and theflame shield 13 having the flanges 37 and 38 suitably brazed to thebracket 12 to secure the burner means 10 together.

A pair of ears 40 and 41 extend outwardly from the depending flanges 37of the flame shield 13 in the manner illustrated in the drawings, theears 40 and 41 respectively having apertures 42 and 43 passingtherethrough. When the aperture 43 in the car 41 is formed, an L-shapedtang 44 is carved therefrom and aligned with the aperture 43 therein fora purpose hereinafter described.

A tang 45 extends from the free end of the ear 40 and is angularlydisposed thereto, the tang 45 having a slit 146 formed therein for apurpose now to be described.

A temperature sensing bulb 47 is adapted to be received in the apertures42 and 43 of the ears 40 and 41 in the manner illustrated in FIGURE 2whereby the free end 48 of the temperature sensing bulb 47 will abutagainst the tang 44 to position the temperature sensing bulb 47 relativeto the flame shield 13, the temperature sensing bulb 47 having itsconduit 49 received in the slit 46 of the tang 45 whereby thetemperature sensing bulb 47 can be simply assembled to the flame shield13 and be positively located relative thereto between the tangs 44 and45 in the manner illustrated in the drawings.

It can be seen that the temperature sensing bulb 47 is disposed spacedfrom the free end 34 of the flame shield 13 so as to be in the path ofthe heater flame 36 in the manner illustrated in FIGURE 6 whereby theheater flame 36 will completely surround the temperature sensing bulb 47to heat the same for any desired purpose.

For example, the temperature sensing bulb 47 can control a valve meansdirecting fuel to the main burner means so that when the temperaturesensing bulb 47 senses the heater flame 36, the valve means will beopened to permit fuel to issue from the main burner means so that thefuel issuing from the main burner means can be ignited by the largestandby flame 30. However, when the heater flame 36 ceases to exist atthe pilot burner means 10 and only the. small standby flame 30 is beingproduced, it can be seen that the temperature sensing bulb 47 isdisposed a suflicient distance away from the flame 30 so that thetemperature sensing bulb 47 will cause the safety valve to close toprevent fuel from issuing from the main burner means.

In particular, reference is made to FIGURES 7 and 8 wherein the improvedsystem of this invention is generally indicated by the reference numeral50 which utilizes the pilot burner means 10 previously described.

The pilot burner means 10 is mounted adjacent a main oven burner 51which is adapted to have thefuel issuing therefrom ignited when thestandby flame 30 of the pilot burner means 10 has increased in size inthe manner illustrated in FIGURE 5 before the heater flame 36 hasreached the temperature sensing bulb 47 for a purpose hereinafterdescribed.

A control device 52 is provided in the system 50 and comprises a housingmeans 53 having suitable passages and cavities formed therein whereby afuel manifold 54 is adapted to be interconnected to a chamber 55 when acontrol knob 56 is disposed in on position thereof to open a valve means57 disposed between the fuel manifold 54 and the chamber 55. The chamber55 is interconnected to a safety valve 58 by a conduit means 59.

The safety valve 58 comprises a housing means 60 having a valve seat 61interconnecting the conduit 59 to a conduit 62 leading to the mainburner means 51, the valve seat 61 being open and closed by a valvemember 63 snapped between its open and closed position by lever andspring means 64.

An expansible element 65 is carried by the safety valve 58 and has amovable wall 66 interconnected to the lever arrangement 64 and a fixedwall 67 fixed to the housing 60, the interior of the expansible element65 being interconnected to the temperature sensing bulb 47 by theconduit 49 previously described.

Thus, as long as the temperature sensing bulb 47 does not sense a heaterflame 36 at the pilot burner 10, the movable wall 66 of the expansibleelement 65 is in such a position that the spring and lever arrangement64 maintains the valve member 63 in its closed position against thevalve seat 61 to prevent the flow of fuel to the burner means 51.

However, when the temperature sensing bulb 47 senses the heater flame 36at the pilot burner means 10, the movable wall 66 of the expansibleelement 65 has moved in such a manner that it causes the spring andlever arrangement 64 to snap open the valve member 63 so that fuel canissue at the main burner means 51 and be ignited by the enlarged standbyflame 30.

However, it can be seen that the pilot burner means 10 is so constructedand arranged in the manner previously described that the standby flame30 has increased to a size in FIGURE 5 to ignite fuel which would issuefrom the burner means 51 well before the time that the heater flame 36is effective to actuate the safety valve 58 to direct fuel to the burnermeans 51 so that there is always an igniter flame 30 at the main burnermeans 51 before the safety valve 58 opens.

The pilot burner 10 is fed fuel from a conduit means 68 interconnectedto the threaded portion 18 of the pilot burner means 10 and to a passagemeans 69 formed in the housing 53. A pilot adjusting key 70 is disposedin the passage means 69 and has an axial bore 71 in alignment therewithand interconnected to transverse bores 72 and 73 respectivelyinterconnected to passage means 74 and 75 in the housing means 53.

The passage means 74 is always interconnected to the fuel manifold 54 ata point downstream from the valve means 57 so that when the adjustingkey 70 is disposed in the position illustrated in FIGURE 8, suflicientfuel small standby flame 30 in the manner illustrated in FIG- URE 4.

The passage means 75 in the housing 53 is interconnected to an outletchamber 76 interconnected to a fuel inlet chamber 77 by a valve seat 78opened and closed by a ball valve 79. The fuel inlet chamber 77 isinterconnected to the fuel manifold 54 by a passage means 80 which isopened and closed by the valve member 57.

A lever 81 is disposed in the chamber 55 and has an intermediate portion82 fulcrumed on the end 83 of an axial, removable adjusting pin 84operatively interconnected to the control knob 56. One end 85 of thelever '81 is operatively interconnected to a movable wall 86 of anexpansible element 87 having the interior thereof interconnected to atemperature sensing bulb 88 by a conduit means 89, the temperaturesensing bulb 88 being disposed in the oven so as to sense thetemperature effect of the main burner means 51 for a purpose hereinafterdescribed.

The other end 90 of the lever 81 carries a plunger 91 adapted to engagethe ball valve 79 for a purpose now to be described.

When it is desired to operate the system 50 of this invention, it can beseen that the small standby flame 30 is always in existence at the pilotburner means 10 when the adjusting key 70 is disposed in the positionillustrated in FIGURE 8, even though the control knob 56 is disposed inits off position to close the valve member 57 in a manner to preventcommunication between the fuel manifold 54 and the passage means 80 andchamber 55.

When only the flame 30 is at the pilot burner means 10, the safety valve58 is disposed in its closed position because the temperature sensingbulb 57 does not have the heater flame 36.

The operator turns the control knob 56 to the desired on positionthereof whereby the valve means 57 is open to interconnect the fuelmanifold 54 to the chamber 55 of the control device 50 as well as to thepassage means 80 thereof.

The rotation of the control knob 56 causes axial adjustment of thefulcrum pin 84 in such a manner that since the temperature sensing bulb88 is sensing a temperature in the oven below the temperature selectedby the control knob 56, the lever 81 is pivoted in such a manner on theend 83 of the fulcrum pin 84 by a compression spring 92 that the ballvalve 79 is moved to an open position thereof whereby an increased flowof fuel is directed to the pilot burner means 10 by means of theadjusting key 70 so that the increased flow of fuel to the pilot burnermeans 10 causes the pilot burner means 10 to increase the standby flame30 thereof in the manner illustrated in FIGURE so that the increasedstandby flame 30 will be sufficiently large to ignite fuel subsequentlyissuing from the main burner means 51. In addition, this additional flowof fuel to the pilot burner means forms the heater flame 36 in themanner illustrated in FIGURE 6 whereby the temperature sensing bulb 47senses the heater flame 36 and causes opening of the safety valve 58whereby fuel can now flow to the main burner means 51 and be ignited bythe enlarged standby flame 30.

The safety valve 58 remains open so that fuel can issue from the mainburner means 51 as long as the temperature of the oven is below thetemperature selected by the control knob 56.

However, when the temperature sensing bulb 88 senses that thetemperature of the oven is at or exceeds the temperature selected by thecontrol knob 56, the expansible element 87 has moved the movable wall 86to the right in FIGURE 8 a distance suflicient to cause the lever 81 toclose the ball valve 79 against the valve seat 78 whereby the increasedflow of fuel to the pilot burner means 10 is terminated so that the samewill only have the small heater flame 30 in FIGURE 4 whereby the safetyvalve 58 will close and terminate the supply of fuel to the main burnermeans 51.

Thus, it can be seen that the main burner means 51 is cycled on and ofiby means of the pilot burner means 10 under the control of thetemperature sensing bulb 88 whereby the temperature of the oven can bemaintained at the temperature selected by the control knob 56.

When it is desired to turn off the system 50, the control knob 56 ismoved to its off position whereby the same closes the valve means 57 inthe manner previously described.

Therefore, it can be seen that the system 50 of this invention is toconstructed and arranged that the same causes a small standby flame 30at the pilot burner means 10 to be increased in size to ignite fuelwhich will issue from the main burner means 51 before the heater flame36 is produced to cause fuel to flow to the burner means 51.

While only one type of pilot burner means 10 has been described for thesystem 50 of this invention, it is to be understood that other types ofburner means can be provided.

For example, reference is made to FIGURES 9-1-4 wherein another pilotburner means 93 of this invention is provided and includes a mountingbracket means 94 carrying an angularly bent conduit 95 having an outletend 96 and an inlet end 97 interconnected to a hollow retainer 98 havinga threaded portion 99 for interconnecting to a fuel supply conduit orthe like. The retainer 98 has a transverse bore 100 provided therein sothat air can be drawn in to the hollow interior of the retainer 98 whenfuel flows therethrough so as to provide an air and fuel mixture at theoutlet end 96 of the conduit 95.

A flame shield 101 is carried by the bracket means 94 and issubstantially U-shaped in cross section and has an end 102 disposed overthe outlet end 96 of the conduit 95. The flame shield 101 has an angularportion 103, FIGURE 12, provided with an opening 104 through which asmall heater flame 105 can issue when a certain amount of fuel issupplied to the pilot burner means 93 in a manner similar to the system50 of this invention.

A tang 106 is carved from the flame shield 102 and is disposed over theoutlet end 96 of the conduit 95 in the manner illustrated in FIGURES 11and 12 to provide a turbulence causing means at the outlet end 96 of theconduit 95 in the manner similar to the tank 31 previously described.

The substantially horizontally disposed straight portion 107 of theflame shield 101 has a plurality of elongated slots 108 provided thereinintermediate the ends 102 and 109 of the flame shield 101.

A pair of ears 110 extend from the end 109 of the flame shield 101 andrespectively have transverse aperture 111 provided therein to receivethe temperature sensing bulb 47 previously described, the upper ear inFIGURE 10 having a tang 112 against which the end 48 of the temperaturesensing bulb 47 can abut.

The lower ear 110 in FIGURE 10 has an angularly bent portion 113provided with a threaded bore therein and in which a threaded member 114can be assembled therewith and abut against a reduced portion 115 of thetemperature sensing bulb 47 to hold the same in assembled relationrelative to the pilot burner means 93.

The pilot burner mean 10 can be provided with the fastening screw 114instead of the slit means 46 thereof and the pilot burner means 93 ofthis invention can be provided with the slit 46 in the flange 113thereof in lieu of the thread member 114, if desired.

When an increased flow of fuel is directed to the conduit 95 in a mannersimilar to that provided by the system 50 of this invention, it can beseen that the standby flame 105 thereof increases in length in themanner illustrated in FIGURE 13, while part of the flame 116 begins tomove to the right and issue through the slots 108. Thus, it can be seenthat the standby flame 105 has increased in size in FIGURE 13 to aposition to ignite fuel at a main burner means long before the flamesensing bulb 47 is activated 7 3y the heater flame 117 for the purposepreviously deicribed.

Therefore, it can be seen that improved pilot burner system means areprovided by this invention as well as improved pilot burner meanswherein the parts are relatively few and simple to manufacture and canbe assembled together in a simple and economical manner to provide arugged pilot burner means adapted to effectively control the operationof a main burner means or the like.

Thus, it can be seen that the pilot burners of this invention can beeasily mounted adjacent the main burner because of the increased standbyflame for ignition purposes whereas the heater flame detector will bedisposed remote from the main burner and not be effected thereby wherebythe problem of locating the pilot burner to provide good ignition isgreatly alleviated by this invention.

Accordingly, this invention not only provides an improved pilot burnersystem means but also this invention provides improved parts for such asystem means or the like.

While the form of the invention now preferred has been disclosed asrequired by the statutes, other forms may be used, all coming within thescope of the claims which follow.

What is claimed is:

1. In a fuel control system, a pilot burner means having a first outletmeans to normally issue a small standby flame during normal flow of fuelto said pilot burner means, and means for increasing the flow of fuel tosaid pilot burner means to increase the size of said standby flame forignition purposes, said pilot burner means having a second outlet meansspaced from and below said first outlet means to produce a heater flameat said second outlet means only when said increased flow of fuel isdirected by said fuel flow means to said pilot burner means.

2. In a fuel control system as set forth in claim 1, said pilot burnermean carrying a heater flame detector adjacent said second outlet means.

3. 'In a fuel control system as set forth in claim 2, said heater flamedetector comprising a temperature sensing bulb.

4. In a fuel control system, a main burner means, a pilot burner meansdisposed adjacent said main burner means and having a first outlet meansto normally issue a small standby flame during normal flow of fuel tosaid pilot burner means, and means for increasing the flow of fuel tosaid pilot burner means to increase the size of said standby flame to asize sufficient to ignite fuel from said main burner means, said pilotburner means having a second outlet means spaced from and below saidfirst outlet means to produce a heater flame at said second outlet meansonly when said increased flow of fuel is directed by said fuel flowmeans to said pilot burner means.

5. In a fuel control system as set forth in claim 4, and meansresponsive to said heater flame adapted to cause fuel to flow to saidmain burner means.

6. In a ffiel control system as set forth in claim 5 said pilot burnermeans being positioned so that said heater flame is disposed remote fromsaid main burner means.

7. In a fuel control system, a main burner, a safety valve for supplyfuel to said main burner, a pilot burner disposed adjacent saidmainburner and having a first outlet means to normally issue a smallstandby flame during normal flow of fuel to said pilot burner, and meansfor increasing the flow of fuel to said pilot burner to increase thesize of said standby flame to a size sufficient to ignite fuel from saidmain burner, said pilot burner having a second outlet means spaced fromand below aid first outlet means to produce a heater flame at saidsecond outlet means only when an increased flow of fuel is directed bysaid fuel flow means to said pilot burner means, and means for sensingsaid heater flame to open said safety valve to direct fuel to said mainburner to be ignited by said increased standby flame.

8. In a fuel control system as set forth in claim 7, said 7 pilot burnermeans including a temperature sensing means that senses said heaterflame and causes opening of said safety valve.

9. In a fuel control system as set forth in claim 7, said fuel flowmeans being thermostatically controlled in response to the temperatureeffect of said main burner.

10. A pilot burner means or the like comprising a conduit means havingan inlet end and an outlet end, said conduit means being bentintermediate the ends thereof to provide a tortuous path between saidinlet and said outlet ends, said conduit means having a tang coveringpart of said outlet end to provide turbulence to the fluid issuing fromsaid outlet end, a flame shield carried by said burner means and havinga first portion extending over said outlet end, said first portionhaving an opening therein through which a flame burning at said outletend can issue, said shield having a second portion angularly disposedrelative to said outlet end, said second portion having a slit thereinand through which a larger flame at said outlet end can issue as thelarger flame is progressing toward the free end of said second portion,and a temperature sensing bulb carried by said burner means adjacent thefree end of said second portion and being so constructed and arrangedthat the flame issuing at the free end of said second portion will bedisposed around said bulb.

11. A pilot burner means or the like as set forth in claim 10 wherein amounting bracket is secured to said conduit means and to said flameshield.

12. A pilot burner means or the like as set forth in claim 10 wherein apair of opposed flanges depend from said portions of said shield wherebysaid shield has a substantially inverted U-shaped cross-sectionalconfiguration.

13. A pilot burner means or the like as set forth in claim 10 wherein apair of opposed ears are carried by said free end of said shield, saidears having aligned apertures receiving said temperature sensing bulb.

14. A pilot burner means or the like as set forth in claim 10 whereinsaid tang is carved from said first portion of said shield.

15. A pilot burner means or the like comprising an outlet end for theissuance of fuel, and a flame shield carried by said burner means andhaving a first portion extending over said outlet end, said firstportion having an opening therein through which a flame burning at saidoutlet end can issue, said shield having a second portion angularlydisposed relative to said outlet end, said second portion having slitmeans therein and through which a larger flame at said outlet end canissue as the larger flame is progressing toward the free end of saidsecond portion, said free end of said second portion being disposedbelow and spaced from said opening.

16. A pilot burner means or the like a set forth in claim 15 wherein apair of opposed flanges depend from said shield so that said shield hasa substantially inverted U-shaped cross-sectional configuration.

17. A pilot iburner means or the like as set forth in claim 15 wherein atemperature sensing bulb is carried by said burner means and is disposedspaced from said free end of said second portion of said shield beyondsaid outlet end.

18. A pilot burner means or the like as set forth in claim 17 whereinthe axis of said temperature sensing bulbis transverse to the directionof the fuel issuing from said outlet end.

19. In a fuel control system, a main burner, a safety valve forsupplying fuel to said main burner, a pilot burn-- er disposed adjacentsaid main burner and normally having a small standby flame, and meansfor increasing the flow of fuel to said pilot burner to increase thesize of-said' standby flame to a size suflicient to ignite fuel fromsaid main burner, said pilot burner having means to produce a heaterflame when an increased flow of fuel is directed by said fuel flowmeans, said pilot burner having means for sensing said heater flame toopen said safety valve to direct fuel to said main burner to be ignitedby said increased standby flame, said pilot burner including a conduitmeans having an inlet end and an outlet end, said conduit means beingbent intermediate the ends thereof to provide a tortuous path betweensaid inlet end and said outlet end, said conduit means having a tangcovering part of said outlet end to produce turbulence to the fluidissuing from said outlet end, a flame shield carried by said pilotburner and having a first portion extending over said outlet end, saidfirst portion having an opening therein through which said standby flamecan issue, said shield having a second portion angularly disposedrelative to said outlet end, said second portion having a slit thereinand through which part of said flame can issue as said flame isprogressing toward the free end of said second portion to provide saidheater flame.

20. A pilot burner means or the like comprising an outlet end for theissuing of fuel, and a flame shield carried by said burner means andhaving a first portion extending over said outlet end, said firstportion having an opening therein through which a flame burning at saidoutlet end can issue, said shield having a second portion angularlydisposed relative to said outlet end, said second portion having slitmeans therein through which a larger flame at said outlet end can issueas the larger flame is progressing toward the free end of said secondportion, said pilot burner means having a pair of ears extending fromsaid free end of said second portion of said shield, and a temperaturesensing bulb being carried by said ears.

21. A pilot burner means or the like as set forth in claim 20 whereinsaid ears have apertures passing the-rethrough and in which saidtemperature sensing bulb is received.

References Cited by the Examiner JAMES W. WESTHAVER, Primary Examiner.

Dedication 3,308,871.Fred Rz'ehl, Greensburg, Pa. PILOT BURNER MEANS ORTHE LIKE. Patent dated Mar. 14, 1967. Dedication filed June 13, 1972, bythe assignee, Robertshaw Controls Company. Hereby dedicates to thePublic the remaining term of said patent.

[Ofioial Gazette January 16, 1.973.]

1. IN A FUEL CONTROL SYSTEM, A PILOT BURNER MEANS HAVING A FIRST OUTLETMEANS TO NORMALLY ISSUE A SMALL STANDBY FLAME DURING NORMAL FLOW OF FUELTO SAID PILOT BURNER MEANS, AND MEANS FOR INCREASING THE FLOW OF FUEL TOSAID PILOT BURNER MEANS TO INCREASE THE SIZE OF SAID STANDBY FLAME FORIGNITION PURPOSES, SAID PILOT BURNER MEANS HAVING A SECOND OUTLET MEANSSPACED FROM AND BELOW SAID FIRST OUTLET MEANS TO PRODUCE A HEATER FLAMEAT SAID SECOND OUTLET MEANS ONLY WHEN SAID INCREASED FLOW OF FUEL ISDIRECTED BY SAID FUEL FLOW MEANS TO SAID PILOT BURNER MEANS.